Avoid running WheelEventTestMonitor-related test-only code when not t…

…esting

https://bugs.webkit.org/show_bug.cgi?id=256934
rdar://109488666

Reviewed by Wenson Hsieh.

RemoteScrollingTreeMac::deferWheelEventTestCompletionForReason() and RemoteScrollingTreeMac::removeWheelEventTestCompletionDeferralForReason()
would always trigger the hop to main thread, and IPC with the web process. We only need to do that when running layout tests
that use `eventSender.monitorWheelEvents()`, and the RemoteScrollingTree already has a bit for that, so use it.

* Source/WebKit/UIProcess/RemoteLayerTree/RemoteScrollingTree.cpp:
(WebKit::RemoteScrollingTree::deferWheelEventTestCompletionForReason):
(WebKit::RemoteScrollingTree::removeWheelEventTestCompletionDeferralForReason):
* Source/WebKit/UIProcess/RemoteLayerTree/mac/RemoteScrollingTreeMac.mm:
(WebKit::RemoteScrollingTreeMac::deferWheelEventTestCompletionForReason):
(WebKit::RemoteScrollingTreeMac::removeWheelEventTestCompletionDeferralForReason):

Canonical link: https://commits.webkit.org/264208@main

Source/WebKit/UIProcess/RemoteLayerTree/RemoteScrollingTree.cpp

@@ -199,7 +199,7 @@ void RemoteScrollingTree::deferWheelEventTestCompletionForReason(ScrollingNodeID
 {
     ASSERT(isMainRunLoop());
 
-    if (!m_scrollingCoordinatorProxy)
+    if (!m_scrollingCoordinatorProxy || !isMonitoringWheelEvents())
         return;
 
     m_scrollingCoordinatorProxy->deferWheelEventTestCompletionForReason(nodeID, reason);
@@ -209,7 +209,7 @@ void RemoteScrollingTree::removeWheelEventTestCompletionDeferralForReason(Scroll
 {
     ASSERT(isMainRunLoop());
 
-    if (!m_scrollingCoordinatorProxy)
+    if (!m_scrollingCoordinatorProxy || !isMonitoringWheelEvents())
         return;
 
     m_scrollingCoordinatorProxy->removeWheelEventTestCompletionDeferralForReason(nodeID, reason);

Source/WebKit/UIProcess/RemoteLayerTree/mac/RemoteScrollingTreeMac.mm

@@ -323,6 +323,9 @@
 
 void RemoteScrollingTreeMac::deferWheelEventTestCompletionForReason(ScrollingNodeID nodeID, WheelEventTestMonitor::DeferReason reason)
 {
+    if (!isMonitoringWheelEvents())
+        return;
+
     RunLoop::main().dispatch([strongThis = Ref { *this }, nodeID, reason] {
         if (auto* scrollingCoordinatorProxy = strongThis->scrollingCoordinatorProxy())
             scrollingCoordinatorProxy->deferWheelEventTestCompletionForReason(nodeID, reason);
@@ -331,6 +334,9 @@
 
 void RemoteScrollingTreeMac::removeWheelEventTestCompletionDeferralForReason(ScrollingNodeID nodeID, WheelEventTestMonitor::DeferReason reason)
 {
+    if (!isMonitoringWheelEvents())
+        return;
+
     RunLoop::main().dispatch([strongThis = Ref { *this }, nodeID, reason] {
         if (auto* scrollingCoordinatorProxy = strongThis->scrollingCoordinatorProxy())
             scrollingCoordinatorProxy->removeWheelEventTestCompletionDeferralForReason(nodeID, reason);